1391729 has 2 divisors, whose sum is σ = 1391730. Its totient is φ = 1391728.

The previous prime is 1391713. The next prime is 1391779. The reversal of 1391729 is 9271931.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1385329 + 6400 = 1177^2 + 80^2 .

It is a cyclic number.

It is not a de Polignac number, because 1391729 - 2⁴ = 1391713 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1391695 and 1391704.

It is not a weakly prime, because it can be changed into another prime (1391779) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 695864 + 695865.

It is an arithmetic number, because the mean of its divisors is an integer number (695865).

2^1391729 is an apocalyptic number.

It is an amenable number.

1391729 is a deficient number, since it is larger than the sum of its proper divisors (1).

1391729 is an equidigital number, since it uses as much as digits as its factorization.

1391729 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3402, while the sum is 32.

The square root of 1391729 is about 1179.7156437040. The cubic root of 1391729 is about 111.6481571261.

The spelling of 1391729 in words is "one million, three hundred ninety-one thousand, seven hundred twenty-nine".